Archive for the ‘Bee-keeping’ Category

NZ experts react to results of field tests on insecticide impact on bees

The Science Media Centre has posted comments (HERE) from New Zealand scientists on two large-scale field experiments on the effects of certain insecticides on honey bees and wild bees.

Neonicotinoids, insecticides that have been broadly applied to many major crops, have been implicated in the decline of bees globally.

Two studies, published this week in Science, found mixed results.

* Insecticide residue in bees nests was associated with lower reproductive success in Germany, Hungary and the UK, but survival over winter was unaffected in Germany.

* The second study, in Canada, found that worker bees exposed to neonicotinoids had lower life expectancies and their colonies were more likely to lose queens.

More information about the studies is available HERE.  

Dr David Pattemore, pollination & apiculture team leader, Plant & Food Research, comments:

“Two new studies published this week claim to show negative effects of neonicotinoids on honey bee colonies in real-world scenarios. One study does not really present clear evidence to support this conclusion, but the second does link neonicotinoid exposure to key longevity, hygiene and reproductive traits of honey bee colonies.

“One of the studies demonstrates synergistic effects between fungicides and neonicotinoids, which increase the mortality of bees exposed to the pesticides. One of the studies shows evidence of negative neonicotinoid effects on bumblebee and solitary bee reproductive output.

“Overall these provide  little more evidence about the effects of neonicotinoids, but there is still no scientific consensus emerging about the effect of neonicotinoids on honey bee health in realistic field situations.

“These two studies are unlikely to have implications for New Zealand in terms of regulations for the use of neonicotinoid pesticides. After reading these papers, my view is that we need to consider the synergistic effects of multiple agrochemicals on bee health and that it is timely to consider establishing long-term monitoring programmes for wild pollinator populations, including native and introduced bees, in New Zealand.”

Note: Dr Pattemore has also written a blog in response to the studies. Plant & Food Research occasionally has contracts to evaluate the efficacy or toxicity of pesticides, but Dr Pattemore hasn’t been personally involved in these trials to date.

Dr Jacqueline Rowarth, chief scientist, Environmental Protection Authority, comments:

“Research published this week indicates that prolonged exposure to neonicotinoid insecticides can negatively affect bees. The researchers also concluded that local environment and species influence impact of the chemicals. The research was done in the northern hemisphere near oilseed rape crops in Germany, Hungary and the UK, and in the commercial corn (maize)-growing area of Canada.

“For New Zealand, and the Environmental Protection Authority (EPA) which regulates the use of chemicals, focus on new research results includes applicability. Experts scan for new research constantly, and consider the results in the New Zealand context.

“New Zealand does not have the large tracts of land under cropping that are common in the northern hemisphere, and does have very strict regulations around timing of chemical application (e.g., not when the target for protection is flowering), delivery method, and seed treatment dust reduction. The northern hemisphere research comments on neonicotinoid dust being found in the pollen of flowering species surrounding crops ‘despite the use of dust-reducing lubricants’.

“In New Zealand the use of neonicotinoids in seed treatment has enabled very low rates of active ingredient, thereby reducing the number of insecticide treatments required to protect the crop. Residues of neonicotinoids have not been found in pollen or nectar of when the insecticide has been applied at label rates.

“The chemical of particular concern in the new research, clothianidin, is a seed treatment approved for cereals, maize/sweetcorn, grasses and forage brassicas. Only the brassica is a flowering crop, and it is eaten before it reaches maturity. The crops are not considered to be attractive to bees, unlike oilseed rape.

“The northern hemisphere researchers also comment on the increase in negative effects in bees when fungicides were used as well as the neonicotinoids and the confounding factor of climate change. This points to the complexity of identifying the problems with chemical exposure. Cold damp winters affect bee survival and there is an interaction with pests as well as food supplies (quantity and quality). These factors are difficult to disentangle. In New Zealand, feral bee numbers have been decimated by varroa mite, but managed bee hive numbers have increased. In Australia, which is varroa-free, no problems with bee survival have been reported. Neonicotinoids have been used for two decades.

‘Recognising on-going public concerns, the EPA is developing a pollinator strategy, working with the chemical industry and the apiculturalists, to ensure that decisions about chemical use are made on the basis of robust and appropriate research, whilst supporting pollinators and pollination.”

The EPA sets the rules for use of hazardous substances under the Hazardous Substances and New Organisms Act 1996 by assessing the environmental and economic risks and benefits to New Zealanders and the environment.

Associate Professor Peter Dearden, director, Genetics Otago, University of Otago, comments:

“The two Science papers (Tsvetkov et al and Woodcock et al) attempt to test the effect of common pesticides on bee colonies in situations that are as close to reality (in terms of exposure) as possible. This is a tricky thing to do, and something that has been criticised in previous studies of neonicotinoid exposure in the past. These papers do this well, and show that the effects of neonicotinoids are complex, but detrimental to bees.

“In Canada, Tsvetkov et al show clearly that neonicotinoid seed coatings have detrimental effects on bees, and that these effects are exacerbated by other agricultural chemicals. Woodcock et al show similar things in Europe, but add that the different cocktails of agricultural chemicals used in different countries have different effects, causing variation in the impact on bees in each location.

“This complexity of response to insecticides is not surprising, but these results clearly show that in general neonicotinoid exposure, even in sublethal doses, in field realistic tests, is detrimental to bees. This is a problem, but so is growing crops without pesticides.

“There is a balance to be had here if we are to produce food in large enough quantities to feed a burgeoning human population, without devastation of managed, and wild, pollinators. The hope of these papers is the variability seen in European countries, and the synergistic effects with other agri-chemicals seen in Canada. This suggests that we may be able to identify ways of using these chemicals, or combinations of these chemicals, to be less damaging to bees, and wild insects.

“The key message is, however, that in field realistic conditions, neonicotinoid seed treatments are bad for pollinators. Limiting their use in New Zealand, as well as researching how to develop pollinator friendly insecticides, or using insecticides in a less damaging way, is critical. The European studies show that agricultural practice varies the impact on bees. We need this research to be done in New Zealand to see how our practice is affecting our bees.”

Note: Dr Dearden has a Ministry of Business, Innovation and Enterprise grant to develop bee-friendly insecticides.

Professor Phil Lester, insect ecologist, Victoria University of Wellington, comments:

“Neonicotinoids are some of the most widely used pesticides in the world. They were developed in the hope that their use would be less harmful to non-target organisms, because by only coating crop seeds in this pesticide prior to planting the need for spraying entire environments can be reduced. Neonicotinoids are then expressed throughout the mature plant and affect only those organisms eating the plant. The issue is that neonicotinoids are expressed in the pollen and nectar too, which beneficial organisms like bees collect and eat.

“The European Union imposed a temporary moratorium on the use of the three key neonicotinoids in 2013 because of their potential to harm honey bees. In contrast, the government of New Zealand has joined with Australia in not imposing a ban or moratorium on the use of these chemicals. I think our governments have made exactly the right decision at this time.

“The work published by Tsvetkov and colleagues in Science today that indicates ‘Chronic exposure to neonicotinoids reduces honey-bee health near corn crops’. This study agrees with a large amount of previous work. If honey bees are exposed to and feed on high amounts of neonicotinoids the outcome is simply bad. Workers and queens will die. For those experiencing a sub-lethal dose, their foraging becomes less efficient. They undertake reduced hygienic behaviour in the hive and their immune system seems to be impaired. And their tolerance of other stressors bees experience in bee environments, in this case a fungicide, is reduced.

“The Tsvetkov study in cornfields of Canada clearly shows that field-realistic exposure to neonicotinoids can substantially reduce honey bee health.

“The second paper in Science today is from work within three different countries and examines three different bees. It also attempted to use field-realistic exposure to neonicotinoids. Populations of honey bees, bumble bees and a solitary bee were followed in the United Kingdom, Hungary and Germany.

“The team of authors led by Woodcock examined two neonicotinoid pesticides. They found a fascinatingly mixed bag of results. Both neonicotinoids resulted in significantly reduced numbers of honey bee eggs being produced in Hungary. But exposure to both pesticides in Germany resulted in significantly more eggs being produced. Neonicotinoids also seemed to result in higher numbers of workers surviving winter in Germany. In Hungary, fewer workers survived winter after exposure to one pesticide, but not the other chemical. Similarly, in the United Kingdom, there were negative and some positive effects of exposure to the different neonicotinoids.

“A take-home message the Woodcock publication is that the use different neonicotinoids can have different effects and these effects can be very country specific. After reading these results, if I was a grower in Germany I would be starting to question the European Union’s temporary moratorium.

“These studies highlight that for countries like New Zealand to effectively manage the use of neonicotinoid pesticides, we need data. We need to know what the effects of neonicotinoids are in our specific country and in the way we specifically use them. And we also need to know what the effects would be if we took them away. I’ve read reports that growers in the UK have had to now revert to broad spectrum pesticides that are considered worse for the environment and mean they cannot grow certain crops.

“In 2013, the Australian government undertook a review of “Neonicotinoids and the Health of Honey Bees in Australia”. They concluded that “the introduction of the neonicotinoids has led to an overall reduction in the risks to the agricultural environment from the application of insecticides”. They don’t currently think there is the scientific evidence to show that neonicotinoids are of widespread harm to bees in Australia. In fact, they stated that “The introduction of the neonicotinoid insecticides has brought a number of benefits, including that they are considerably less toxic to humans (and other mammals) than the organophosphorus and carbamate insecticides they have significantly replaced.

“Honey bees in New Zealand have a plethora of known and scientifically demonstrated threats. Our honey bees have invasive, blood sucking mites. They have the Deformed wing virus which has been described as a key contributor to colony collapse around the globe. Our bees have bacterial pathogens like American Foulbrood that result in beekeepers burning their bees and hives. Fungal diseases are widespread. We also have management issues with the higher-than-ever numbers of managed hives, which are often managed poorly and over-stocked. These are real and known issues occurring for our honey bees now.

“I hope that the New Zealand government acts on studies like those from the Woodcock and Tsvetkov teams.

“But I’d personally be disappointed if that action was anything other than evidence- and science-based. Let’s gather the data. Then make the decision. It might be that like results from the Tsvetkov study, we find neonicotinoids are bad for our bees. Or we might be a Germany and find that they have few or even positive effects.”

Note: Professor Lester’s comments also appeared on The Conversation.

Survey shows NZ honey bee loss is lower than in other countries

New Zealand’s honey bee population is growing, according to the 2016 NZ Colony Loss and Survival Survey, which shows New Zealand’s honey bee loss is low on an international scale.
Colony deaths from starvation, queen problems and wasps accounted for 87.3 per cent of losses in the 2016 winter season. Losses averaged 9.78 per cent, down from 2015 and over 2 per cent lower than the northern hemisphere average.
Hive numbers have increased 20 per cent between March 2015 and June 2016. The challenges for beekeepers include competition for apiary sites, lost pollen and nectar sources, according to the survey.
Agcarm chief executive Mark Ross said:

“The survey is critical not only because it informs us on bee health, but because it allows us to make better choices to protect our bee population and to track changes on colony loss and survival for the future.
“The report shows that we still have some work to do – to make sure our bees are well-fed and protected from wasps. But, overall, our bee population is thriving – which is good news, especially with all the hype we hear about bee loss.”

Agcarm will continue to work with the bee industry to help ensure a healthy bee population.

Plant & Food scientists report a breakthrough for the bees

Preliminary results from a pilot study undertaken by scientists at Plant & Food Research indicate that a breakthrough has been made in the fight against the pathogen Nosema ceranae, a deadly disease for bees.

This relative newcomer to New Zealand is a cousin of Nosema apis, which has been present in the country since the 1800s.

Both N. apis and N. ceranae are spore-producing parasites that attack the gut lining of bees, leading to a shortened lifespan in adults. Severe cases of N.ceranae may cause the collapse of an entire colony.

Because Nosema is primarily spread through faeces on contaminated honeycomb, preventing infection is a near-impossible task, meaning the commercial costs associated with Nosema infection have simply been “a fact of life”.

During the springs of 2014 and 2015 many New Zealand beekeepers, particularly in the Coromandel, experienced severe and unexplained colony losses. This pattern had not been experienced before and resulted in honey loss estimated at between 40-60% for the season.

N. ceranae had first been found in New Zealand in 2010 and was identified as a potential culprit for the calamity.

In response, a team from Plant & Food Research began working closely with Coromandel beekeeper Dr Oksana Borowik – first confirming high levels of N. ceranae in affected colonies, and then exploring ways to prevent the spread of the disease between hives.

Their early research findings have been announced in a press release from Pland & Food: heat-treating the hive and internal comb to only 50C for 90 minutes resulted in an increase in brood viability and a 50% increase in adult bee numbers.

The treatment is effective because heat kills N. ceranae spores lurking on contaminated comb before the new colony is introduced to the hive.

“Nosema ceranae has had a notable impact on hives and the honey industry in countries like the United States and China,” says Plant & Food Research scientist Dr Mark Goodwin.

“We need to take the threat of this disease very seriously, particularly as the honey industry and the pollination services of honey bees are very important to New Zealand’s economy.

“The initial findings of this research are a very encouraging first step in the fight against this threat.”

The team will build on this initial study with further investigations into the effect of seasonality and long-term treatment on bee populations.

If heat treatment is found to be a safe and consistent management option for beekeepers plagued by Nosema, there is the potential to greatly improve the health and productivity of New Zealand beehives.

Lincoln researchers calculate the financial sting from the loss of honeybees

New Zealand agriculture stands to lose $295-728 million annually if the local honeybee population continues to decline, according to a new study into the economic consequences of a decline in pollination rates.

One of the co-authors of the study, Lincoln University Professor Stephen Wratten of the Bio-Protection Research Centre, says it is well known that a global decline in the populations of insect pollinators poses a major threat to food and nutritional security.

He says:

“We’ve lost most of our wild bees in New Zealand to varroa mite, and cultivated bees are becoming resistant to varroa pesticides. Functioning beehives are becoming increasingly expensive for farmers to rent. We know the decline in bee populations is going to have a major impact on our economy, but we wanted to measure the impact.”

Previous methods of estimating the economic value of pollination have focused on desktop calculations around the value of crops and the dependency of those crops on pollinators. Professor Wratten says the experimental manipulation of pollination rates is a more direct estimation of the economic value of pollination, or ecosystem services (ES).

A study was conducted in commercial fields producing pak choi for seed production. Some of the plants were covered with thin white mesh bags for varying time periods, preventing honeybees and fly species, which are key pollinators for the crop, from accessing the plants. Changes in seed yield, seeds per pod and proportion of unfertilised pods as a result of changing pollination rates were identified. The economic impact of varying pollination rates was then extrapolated to the main 18 pollination-dependent crops in New Zealand.

The economic impacts of loss of pollinators include higher prices for consumers as crop yields are reduced and food production costs increase.

“It’s critical to understand marginal changes in ES and their economic consequences in order to identify appropriate policy responses and avert further losses,” says Professor Wratten.

“Modifying existing agricultural systems to enhance ES requires a range of mechanisms, such as payments for ES. Current policies at a national and global level continue to largely ignore the value of ES contributions such as biological control and pollination.”

Professor Wratten says farmers worldwide need help to put appropriate diversity back into their lands.

“There is a lot of scientific knowledge accumulating but this has to be turned into ‘recipes’ for end users like farmers to understand and implement. The big challenge is to have a recipe that works. Give farmers the right seeds to plant. Make sure the bees get what they need. It’s not about planting pretty flowers. It’s the science that counts.

“The best way to deliver this is through what we might call ‘farmer teachers’ – farmers who understand and use the recipe, who will get out into the paddock and be listened to by other farmers.”

Dr Mark Goodwin wins apiculture award

Dr Mark Goodwin, a Plant & Food Research scientist who specialises in honey bee and hive health and the pollination services provided by bee colonies, has won the inaugural Apiculture New Zealand Peter Molan Award.

The award and associated research grant recognises his outstanding contribution to science which advances the apiculture industry.

Dr Goodwin’s research has put him at the forefront of the fight against pests and diseases such as Varroa, American foulbrood and, most recently, Nosema ceranae.

Of particular significance, he was a key contributor to far-reaching work on kiwifruit pollination, and has conducted important research in honey bee toxicity. His research has often led to changes in industry practice and policy. He has also been a leading spokesperson for the apiculture industry.

Dr Peter Molan, after whom the award is named, was a pioneer of New Zealand’s apiculture industry, particularly in his work on the health benefits of mānuka honey.

 

Nitrogen loss research benefits from scholarship

Sheree Balvert, a second-year University of Waikato student who is looking into the environmental benefits of feeeding cows brassicas, has been awarded the $10,000 2016 Pukehou Pouto Scholarship.

The scholarship is awarded annually to students from any New Zealand university for postgraduate study in either agricultural science or silvicultural (forestry) science.

Sheree is researching the impact of feed change in cows and whether feeding them forage brassicas such as turnips, swedes and kale affects the nitrogen cycle. This could reduce nitrogen loss in agricultural systems such as dairy or dry-stock farms.

“Cows are inefficient feeders with 70-95% of the nitrogen they eat being excreted in their waste,” she says. “The concentrated urine patches that are deposited onto the ground contain more nitrogen than the plants and microbes in the soil can process, and the excess nitrogen is lost as nitrous oxide gas or as nitrate leaching out of the soil.”

Sheree is supervised by Professor Louis Schipper, at the University of Waikato, and Dr Jiafa Luo, at AgResearch. Her research is funded by the New Zealand Agricultural Greenhouse Gas Research Centre and the Pastoral Greenhouse Gas Research Consortium. Her stipend is also provided by the New Zealand Agricultural Greenhouse Gas Research Centre.

 

Survey finds queen problems are the biggest health issue for bees

New Zealand honey bee population is growing and bee losses are low on an international scale, the inaugural NZ Colony Loss and Survival Survey has found.

Queen problems were the main contributing factor to the honey bee losses, which averaged 10.73 per cent over the 2015 winter season. This is because a well-mated healthy queen drives the reproduction and growth of a colony, according to the report.

Starvation was the most common cause for colony loss. Weak, unhealthy, and sick bees are less likely to survive wintering, which leads to losses of entire colonies.

The survey found the parasitic varroa mite is also one of the biggest challenges to the health of the bee population. Evidence of the mite ranged from 72.7 per cent in Marlborough/Nelson/West Coast area to 28 per cent in Otago/Southland (the last region of New Zealand to be infested by varroa).

Agcarm chief executive, Mark Ross says:

“The survey is critical not only because it informs us on bee health, but because it allows us to make better choices to protect our bee population and to track changes on colony loss and survival for the future.

“The report shows that we still have some work to do – to make sure our bees are well-fed; freed of varroa; and protected from wasps. But, overall, our bee population is thriving – which is good news especially after all of the over-dramatised aspersions on the state of our pollinators.”

The survey was conducted in October 2015 by Landcare Research. It was funded by Agcarm, the Ministry for Primary Industries, National Beekeepers Association and Federated Farmers Bee Industry Group.